In obese individuals, a 21-gauge needle will be needed, especially if injecting the buttock, in order to get as deep as the muscle layer. Injection into subcutaneous fat leads to poor absorption and occasionally to inflammation of the fat.
At some time, you will be asked to perform IM injection in a confused, disturbed individual – often with the aim of sedation. This is permissible under common law, as long as you satisfy yourself that the patient is incapable of informed consent and that your actions are in the best interests of the patient. Think carefully before administering IM sedation to a confused patient who is wandering at night – ask yourself if you have been asked to do it because the nursing staff want a quiet night shift!
If you do administer sedation to a disturbed patient, ensure that you put your own safety first. A flailing arm plus a contaminated needle is a recipe for a needle-stick injury and possible blood-borne infection. Get someone to help you, perhaps by gently restraining flailing arms or by talking to distract the patient.
[back to top]